The Bible describes a miraculous event in which many faithful people who had died rose from their graves and appeared to people in Jerusalem after Jesus Christ died on the cross and came back to life himself. Here's the dramatic story of dead people appearing among the living then:
Matthew 27:51 describes a powerful earthquake that occurred after Jesus’ death on the cross for the sins of the world: "At that moment the curtain of the temple was torn in two from top to bottom. The earth shook, the rocks split..."
Verses 52 and 53 report that, after Jesus’ own resurrection from the dead, many holy people who had been buried also came back to life. They could escape from their tombs because the earthquake that rocked Jerusalem when Jesus died had broken them open: "...and the tombs broke open. The bodies of many holy people who had died were raised to life. They came out of the tombs after Jesus’ resurrection and went into the holy city and appeared to many people."
Since it was important to the faithful at that time and place to venerate the graves of holy people who had passed away, they would have been especially impressed by seeing dead people they had known much about appear to them in person. They would have seen this miraculous sign as a testimony that Jesus has overcome death and made eternal life possible for those who place their trust in him.
After the earthquake that happened at the moment of Jesus’ death on the cross, the Bible says that another earthquake occurred at the moment of his resurrection. Matthew 28:2-4 describes an angel rolling back the stone in front of Jesus’ tomb right after Jesus came back to life: "There was a violent earthquake, for an angel of the Lord came down from heaven and, going to the tomb, rolled back the stone and sat on it. His appearance was like lightning, and his clothes were white as snow. The guards were so afraid of him that they shook and became like dead men." The people who came out of their own graves after Jesus’ resurrection experienced both earthquakes.
This story foreshadows the final resurrection of the dead, which the Bible says will occur at the end of the world.
The story concludes in Matthew 27:54 with the reaction of Roman soldiers guarding Jesus’ tomb, who witnessed the miraculous events: "When the centurion and those with him who were guarding Jesus saw the earthquake and all that had happened, they were terrified, and exclaimed, 'Surely he was the Son of God!'"